1. Field of the Invention
The present invention relates to a valve device, and more particularly to a safety valve device for an inflatable apparatus, which has a check valve to keep air from leaking from the inflatable apparatus and a manual seal assembly to selectively seal the inflatable apparatus.
2. Description of Related Art
Inflatable apparatuses such as inflatable mattresses, sofas or swimming pools generally have a valve device. The valve device is connected to an air pump when the inflatable apparatus is inflated so the air pump can pump air through the valve into an internal air chamber.
A conventional valve device is mounted on the inflatable apparatus and has a body and a check valve. The body has an inner surface. The check valve has a valve stem and a diaphragm and is mounted movably in the body and hermetically contacts the inner surface to keep air from leaking from the inflatable apparatus.
However, the check valve cannot prevent ambient matter such as dust from passing through the valve device. The ambient matter accumulated between the diaphragm and the body causes leakage.
With reference to FIGS. 8 and 9, another valve device for the inflatable apparatus is disclosed in the U.S. Pat. No. 5,941,272. The valve device has a hollow body, a framework (60), a valve stem (70) and a diaphragm (80).
The body has an inner surface.
The framework (60) is mounted in the body and has a recess having an inner surface and a positioning protrusion (61) extending inward from the inside surface.
The valve stem (70) is hollow, is mounted slidably and rotatably in the framework (60) and has an outer surface, a positioning protrusion (71), an abutment protrusion (72) and a spring. The positioning and abutment protrusions (71, 72) protrude out from the outer surface of the valve stem (70). The spring is mounted between inner surface of the recess of the framework and the valve stem (70) and biases the valve stem up.
The diaphragm (80) is mounted on the valve stem (70) and hermetically contacts the inner surface of body to prevent leakage when the positioning and abutment protrusions (71, 72) are located above the positioning protrusion (61) on the framework (60). The diaphragm (80) is disengaged from the inner surface of the body to deflate an inflatable apparatus connected to the valve device when the positioning protrusion (61) on the framework (60) is located above the positioning protrusion (71) on the valve stem (70) and abuts the abutment positioning protrusion (72).
However, the aforementioned valve device can not prevent ambient matter from accumulating between the diaphragm and the body. Leakage still happens due to the accumulated matter.
To overcome the shortcomings, the present invention provides a safety valve device with a manual seal assembly for an inflatable apparatus to mitigate or obviate the aforementioned problems.